The present invention relates to a crane installation, such as a container crane.
Nothing in the following discussion of the state of the art is to be construed as an admission of prior art.
Crane installations are typically used for transshipping goods, whereby container crane installations are provided for transfer of large containers of typical size between 20 foot and 45 foot, for example for loading and unloading ships of freight cars etc. Such a crane installation is normally provided with a horizontally displaceable trolley from which a load-carrying device, e.g. a container spreader, is suspended and intended for grabbing a load to be moved. Personnel operating the crane installation or working in proximity of the crane installation are exposed to danger during crane operation and movement of a load, primarily containers of very large dimensions and of a weight of several tons. Therefore, the crane installation is equipped with safety features by which a stored-programmable control unit is able to shut down operation of the crane if required. Examples of such safety features include emergency shutdown, emergency halt, emergency limit switch supervision, pre-limit switch supervision, overload supervision, or overspeed supervision.
However, for a number of reasons, the various proposals are endowed with drawbacks and shortcomings relating for example to manufacturing techniques or to the effect that is hoped to be obtained but may not always be realized.
It would therefore be desirable and advantageous to provide an improved crane installation to obviate prior art shortcomings.